#include<bits/stdc++.h>
#define int long long
using namespace std;
char buf[1<<23],*p1=buf,*p2=buf,obuf[1<<23],*O=obuf;
#define getchar() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<21,stdin),p1==p2)?EOF:*p1++)
inline int read()
{
    int x=0,f=1;char ch=getchar();
    while(!isdigit(ch)){if(ch=='-') f=-1;ch=getchar();}
    while(isdigit(ch)) x=x*10+(ch^48),ch=getchar();
    return x*f;
}
inline void write(int x)
{
    if(!x)
        putchar('0');
    char F[200];
    int tmp=x>0?x:-x;
    if(x<0)
        putchar('-');
    int cnt=0;
    while(tmp>0)
        F[cnt++]=tmp%10+'0',tmp/=10;
    while(cnt>0)
        putchar(F[--cnt]);
}
const int maxn=1e5+10;
int a[maxn];
signed main()
{
    freopen("trade.in","r",stdin);
    freopen("trade.out","w",stdout);
    int n;
    cin>>n;
    int fl=0;
    for(int i=1;i<=n;i++)
    {
    	cin>>a[i];
    	if(a[i]==0)fl++;
	}
    if(fl)puts("0");
	else puts("1");	
    return 0;
}
